1. Earth’s Surface
Minerals & Rocks

2. Minerals vs. Rocks
A mineral is a solid formation that occurs naturally in the Earth.
A rock is a solid combination of more than one mineral formations which is also occurring naturally.

3. Characteristics of Minerals and Rocks
pure (made of same substance)
more than one mineral
some have crystals
not single crystals
usually pretty
not usually as pretty
usually have a shape
no definite shape
color is usually the same
color is not the same
no fossils
some have fossils

4. Applications of Minerals and Rocks
The commercial value of minerals is immense
Rocks are mined to extract these minerals

5. Rock Words
mountain - huge, giant hunk of rock that is still attached to the earth's crust, doesn't move, tall
boulder - large, taller than a person
rock - large, you could get your arms around it or a bit smaller but it is usually jagged, broken off a bigger piece of rock
river rock - round rocks that are along the edge & at the bottom of fast-flowing rivers
stone - medium, you could hold it in two hands

6. Rock Words
pebble - small, you can hold it with two fingers, could get stuck in your shoe, usually rounded
sand - made up of tiny pieces of rock, grains of sand
grain - tiny, like a grain of rice or smaller, often found on a beach
dust - really fine powder that is mixed in with sand or soil
speck - as in a speck of dirt

7. Minerals
A mineral is the same all the way through. That is one reason we speak of a sample or a specimen rather than a rock.
There are about 3000 known minerals on earth.
All rocks are made up of 2 or more of these minerals.

9. What is a Mineral? Naturally occurring Inorganic- not living Solid
Crystal Structure
Definite chemical composition

10. Properties of Minerals
Color– this varies depending on the chemicals present and is the least informative in identifying a mineral variety
Luster – what the surface looks like in the light
Specific Gravity– how heavy it feels
Crystal Form – shape of crystal, shape the mineral would take if it had room to grow in a cavity

11. Properties of Minerals
Cleavage– pattern when mineral is broken
Fracture Tendency- toughness, how cohesive the mineral is, if it falls apart
Hardness– what it can scratch & what scratches it
Transparency - The ability to transmit light.

12. Luster
Determined by the intensity or quality of the light reflected by its surface

13. Luster
Metallic
Glassy

14. Luster
Waxy/Greasy
Pearly

15. Luster
Dull
Silky

16. Hardness Mohs hardness scale
Ranks ten minerals from softest to hardest
Can be determined by a scratch test.
A mineral can scratch any mineral softer than itself, but can be scratched by any mineral that is harder.

17. Streak The color of its powder.
Color of a mineral may vary…its streak does not.
Color of mineral and streak can often be different.

18. Characteristics/Properties of Minerals
Naturally Occurring
Inorganic
Solid
Crystal Structure
Definite Chemical Composition

19. Properties used to identify minerals
Color- provides little information
Streak- color of mineral’s powder
Luster- how light is reflected from a mineral’s suface
Hardness- determined by a scratch test.
Density- mass per unit of volume.
Crystal Systems-
Cleavage and Fracture

20. Cleavage vs. fracture Cleavage Fracture
A mineral that splits easily along flat surfaces.
Arrangement of the atoms causes it to break more easily in one direction
How a mineral looks when it breaks apart in an irregular way.
Quartz